A conventional means of driving a vehicle, such as a rider-type lawnmower or small tractor, is to interconnect the output shaft of a gasoline engine to a belt drive for operating a transaxle or transmission which is joined to the drive wheels of a vehicle. Such an arrangement usually suffers one or more of the following shortcomings:
1. difficulty in adjusting the vehicle's ground speed in small increments;
2. the necessity of having separate clutch and brake mechanisms for interrupting the wheel drive and for stopping the vehicle; and
3. the problem of excessive acceleration when a clutch is disengaged with the belt drive set for high speed operation, or when the engine is started with the belt drive at its high speed setting.